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Thomas A Depner

Publications and source records attributed to Thomas A Depner.

At least 19 recordsLinked to original sources
PubMed2006

Effect of change in vascular access on patient mortality in hemodialysis patients.

BACKGROUND: Hemodialysis patients using a catheter have a greater mortality risk than those using an arteriovenous (AV) access (fistula or graft). However, catheter-dependent patients also differ from those with an AV access in several clinical features, and these differences may themselves contribute to their excess mortality. METHODS: The current study evaluates whether a change in vascular access affects risk for mortality in patients enrolled in the Hemodialysis Study. Time-dependent Cox regression was used to relate mortality risk to current type of access and change in access type during the preceding 1 year. RESULTS: Compared with patients who dialyzed using an AV access at both the beginning and end of the preceding 1-year interval, relative risks for mortality were 3.43 (95% confidence interval [CI], 2.42 to 4.86) in patients who dialyzed with a catheter at both times; 2.38 (95% CI, 1.76 to 3.23) in patients switching from an AV access to a catheter, and 1.37 (95% CI, 0.81 to 2.32) in patients switching from a catheter to an AV access. Change from AV access to a catheter was associated with an antecedent decrease in serum albumin level (odds ratio, 1.25; 95% CI, 1.09 to 1.45 per 0.5 g/dL; P = 0.002), weight loss (odds ratio, 1.14; 95% CI, 1.06 to 1.22 per 2 kg; P < 0.001), and decreases in equilibrated normalized protein catabolic rate (odds ratio, 2.22; 95% CI, 1.41 to 3.57 per 0.25 g/kg/d; P < 0.001) and non-access-related hospitalization (odds ratio, 1.19; 95% CI, 1.06 to 1.32 per 1 additional hospitalization over 4 months; P = 0.002). Change from a catheter to AV access was predicted by only the antecedent non-access-related hospitalization rate (odds ratio, 0.93; 95% CI, 0.87 to 0.97 per 1 additional hospitalization over 4 months; P < 0.001). CONCLUSION: Change from a catheter to AV access is associated with a substantial decrease in mortality risk.

Arteriovenous Shunt, Surgical↗
PubMed2005

The spectrum of infection-related morbidity in hospitalized haemodialysis patients.

BACKGROUND: Infection is a common cause of mortality and morbidity in haemodialysis patients. Few prospective studies have examined the clinical consequences of infection-related hospitalizations in haemodialysis patients or the risk factors predictive of clinical outcomes. METHODS: The outcomes of all first infection-related hospitalizations of patients enrolled in the HEMO Study were categorized in terms of mortality, requirement for intensive care unit (ICU) stay and length of hospitalization. In addition, the association of hospitalization outcomes with clinical and laboratory parameters was evaluated. RESULTS: Among the 783 first infection-related hospitalizations, 57.7% had a severe outcome (death, ICU stay or hospitalization >/=7 days). The likelihood of a severe outcome increased with patient age (P<0.0001) and with decreased serum albumin (P<0.001). The frequency of a severe outcome varied greatly by infectious disease category (P<0.001), being highest for cardiac infections (95.6%) and infection of unknown source (68.4%), and lowest for urinary tract infections (35.5%) and access-related infections (43.8%). On multivariate analysis, hospitalization outcome was independently associated with patient age, serum albumin and disease category, but not with the randomized Kt/V or flux, gender, race or diabetic status. CONCLUSION: In summary, infection-related hospitalizations are associated with substantial morbidity. Patient age, serum albumin and infectious disease category are independently correlated with the hospitalization outcome, and can be used to estimate the likelihood of serious outcomes at the time of hospital admission.

Adult↗
PubMed2005

Design of the Dialysis Access Consortium (DAC) Aggrenox Prevention Of Access Stenosis Trial.

BACKGROUND: Surgically created arteriovenous (AV) grafts are the most common type of hemodialysis vascular access in the United States, but fail frequently due to the development of venous stenosis. The Dialysis Access Consortium (DAC) Aggrenox Prevention of Access Stenosis Trial tests the hypothesis that Aggrenox (containing dipyridamole and aspirin) can prevent stenosis and prolong survival of arteriovenous grafts. METHODS: This is a multicenter, randomized, double-blind, placebo-controlled trial that will enroll 1056 subjects over four years with one-half year follow-up. Subjects undergoing placement of a new AV graft for hemodialysis are randomized to treatment with Aggrenox or placebo immediately following access surgery. The primary outcome is primary unassisted patency defined as the time from access placement until thrombosis or an access procedure carried out to maintain or restore patency. The major secondary outcome is cumulative access patency. Monthly access flow monitoring is incorporated in the study design to enhance detection of a hemodynamically significant access stenosis before it leads to thrombosis. RESULTS: This paper describes the key issues in trial design, broadly including: 1) ethical issues surrounding the study of a clinical procedure that, although common, is no longer the clinical intervention of choice; 2) acceptable risk (bleeding) from the primary intervention; 3) inclusion of subjects already receiving a portion of the study intervention; 4) inclusion of subjects with incident rather than prevalent qualifying clinical conditions; 5) timing of the study intervention to balance safety and efficacy concerns; and 6) the selection of primary and secondary study endpoints. CONCLUSIONS: This is the first, large, multicenter trial evaluating a pharmacologic approach to prevent AV graft stenosis and failure, an important and costly problem in this patient population. Numerous design issues were addressed in implementing the trial and these will form a roadmap for future trials in this area.

Algorithms↗
PubMed2004

Dose of dialysis: key lessons from major observational studies and clinical trials.

Analyses based on the National Cooperative Dialysis Study (NCDS) provided the impetus for routine quantification of delivered dialysis dose in hemodialysis practice throughout the world, by suggesting minimum targets for small solute (urea) clearance. Morbidity and mortality in dialysis populations remain high despite many technological advances in dialysis delivery. A number of observational studies reported association between higher dose of dialysis as measured by Kt/V urea or urea reduction ratio with lower mortality risk. During the 1990s, a steady increase in dialysis dose and a modest reduction in mortality on dialysis were observed. However, observational studies only reveal associations and are limited by selection bias and confounding. The Kidney Disease Outcomes Quality Initiative guidelines on dialysis adequacy are based on results of observational studies and expert opinion. Since the NCDS, the HEMO Study was the first major randomized clinical trial designed to study the effect of dose of dialysis and dialyzer flux on patient outcomes. Despite adequate separation of dose and flux, however, results of the trial did not prove a beneficial effect of higher dose. The Dialysis Outcomes and Practice Patterns Study (DOPPS), in a major international effort designed to examine the effect of practice patterns on outcomes, has made significant contributions to the topic of dialysis dose. The following review critically examines data from observational studies, including the DOPPS, and from the HEMO Study, emphasizing important lessons from both, and discusses future paradigms for achieving dialysis adequacy to improve patient outcomes.

Humans↗
PubMed2004

Factors that affect postdialysis rebound in serum urea concentration, including the rate of dialysis: results from the HEMO Study.

Previous studies have suggested that postdialysis urea rebound is related to K/V, the rate of dialysis, but a systematic analysis of factors that affect rebound has not been reported. With the use of 30-min and, in a subset, 60-min postdialysis samples, postdialysis urea rebound was measured to (1) determine how well previously proposed equations based on the rate of dialysis (K/V) predict rebound in a large sample of patients with varying characteristics, (2) determine whether other factors besides K/V affect rebound, and (3) estimate more precise values for coefficients in prediction equations for rebound. Rebound was calculated relative to both immediate and 20-s postdialysis samples to study early components of rebound unrelated to access recirculation. The equilibrated Kt/V (eKt/V) computed by fitting the two-pool variable volume model to the 30-min postdialysis sample agreed well with eKt/V based on the 60-min postdialysis sample. Using the pre-, post-, and 30-min postdialysis samples for 1245 patients with arteriovenous (AV) accesses, the median intercompartmental mass transfer coefficient (Kc) was 797 ml/min for rebound computed relative to the 20-s postdialysis samples and 592 ml/min relative to the immediate postdialysis samples. K/V was the strongest predictor of rebound among 22 factors considered. Other factors associated with greater rebound for 1331 patients using AV accesses or venous catheters included access type, black race, male gender, absence of congestive heart failure, greater age, ultrafiltration rate, and low predialysis or intradialysis systolic BP. Equations of the form eKt/V = single-pool Kt/V - B x (K/V) were fit to the data. With AV access, the optimum values for the slope term (B) were 0.39 and 0.46 (in h(-1)) for single-pool Kt/V calculated based on 20-s postdialysis or immediate postdialysis samples, respectively. For patients using venous catheters, the respective values for B were 0.22 and 0.29. Postdialysis urea rebound can be predicted with acceptable accuracy from a postdialysis sample using a zero-intercept, K/V-based rate equation. Several patient or treatment-specific factors predict enhanced or reduced rebound. Rate equation slope coefficients for K/V of 0.39 (AV access) and 0.22 (venous access) are proposed when a 15- to 20-s slow-flow method is used to draw the postdialysis blood. Slightly higher K/V slope coefficients (0.46 and 0.29, respectively) should be used if a shorter (e.g., 10 s) slow-flow period is used.

Female↗
PubMed2004

Increasing dialysate flow and dialyzer mass transfer area coefficient to increase the clearance of protein-bound solutes.

Clinical hemodialysis systems achieve high single pass extraction of small solutes that are not bound to plasma proteins. But they clear protein-bound solutes much less effectively. This study examines the extent to which clearance of a protein-bound test solute is improved by increasing the dialyzer mass transfer area coefficient (KoA) and the dialysate flow rate (Qd). A reservoir containing test solutes and artificial plasma with albumin concentration approximately 4 g/dl was dialyzed with a standard clinical dialysate delivery system. The clearance of phenol red (ClPR) was compared with the clearances of urea and creatinine at a plasma flow rate (Qp) of 200 ml/min with varying values of KoA and Qd. ClPR increased from 11 +/- 2 ml/min to 23 +/- 2 ml/min when KoA for phenol red, KoAPR, was increased from 238 to 640 ml/min and Qd was increased from 286 +/- 6 ml/min to 734 +/- 9 ml/min. Increasing either KoAPR or Qd alone had lesser effects. Clearance values for phenol red were much lower than clearance values for the unbound solutes urea and creatinine, which ranged from 150 to 200 ml/min and were less affected by varying KoA and Qd. A mathematical model was developed to predict ClPR from values of Qp, Qd, the fraction of phenol red bound to albumin (94% +/- 1%) and KoAPR. The model accurately predicts the pattern of measured results and shows further that ClPR can be made to approach Qp only by very large increases in both KoAPR and Qd.

Albumins↗
PubMed2004

Kinetics of urea and beta-microglobulin during and after short hemodialysis treatments.

BACKGROUND: Daily short hemodialysis (HD) is often prescribed by simply doubling treatment frequency and halving treatment time; however, the effect of this prescription approach on the equilibrated HD dose (urea eKt/V) and whole body clearance for beta(2)-microglobulin has not been established. METHODS: We compared urea and beta(2)-microglobulin kinetics during and 60 minutes after a short HD treatment and a conventional HD treatment in a crossover study on 22 maintenance HD patients: 16 male and 6 female, 61 +/- 18 (mean +/- standard deviation) years of age. One patient in each treatment modality was excluded from certain analyses because of missing data. Short and conventional HD treatments were essentially identical, except for treatment times, which were 116 +/- 14 and 241 +/- 27 minutes, respectively. Blood samples were collected at regular intervals during and after treatments, and additional blood and dialysate samples were collected at 60 minutes of treatment to evaluate dialyzer clearances. RESULTS: Plasma water urea clearances measured directly across the dialyzer during short and conventional HD treatments were not different (255 +/- 23 mL/min and 255 +/- 28 mL/min, respectively). The 60-minute postdialysis blood urea nitrogen concentration rebounded more (P < 0.01) after short HD than conventional HD (5.9 +/- 3.1 vs. 4.0 +/- 1.5 mg/dL, respectively). Calculated urea eKt/V values using the Daugirdas-Schneditz rate equation were not different from those measured during conventional HD using the 60-minute postdialysis concentration but significantly overestimated measured urea eKt/V values during short HD. Postdialysis rebound of beta(2)-microglobulin concentrations was variable but similar after short and conventional HD treatments (0.1 +/- 3.4 vs. 0.7 +/- 1.8 mg/L, respectively). Whole body clearances of beta(2)-microglobulin calculated from predialysis and immediate (10-second) postdialysis serum concentrations during short and conventional HD treatments were not different from each other (42.9 +/- 24.1 vs. 41.9 +/- 22.4 mL/min, respectively). CONCLUSION: These observations show that the Daugirdas-Schneditz rate equation is accurate in predicting urea eKt/V during conventional, but not during short, HD. In contrast, whole body clearances of beta(2)-microglobulin during short and conventional HD treatments were similar. We conclude that calculation of accurate estimates of urea eKt/V, but not clearances of beta(2)-microglobulin, differ during short and conventional HD treatments.

Blood Urea Nitrogen↗
PubMed2003

Adequacy of quotidian hemodialysis.

BACKGROUND: Several methods exist to quantitate small-solute clearance by daily hemodialysis (HD) regimens, but these have not been empirically applied or compared. METHODS: In the London Daily/Nocturnal Hemodialysis Study, dosing and adequacy of quotidian HD regimens, both short daily HD (n = 11) and long nocturnal HD (n = 12), were compared with conventional thrice-weekly HD (n = 22) using several models. Urea clearance was computed by percentage of reduction in urea, kinetic modeling (single-pool Kt/V [spKt/V]), Daugirdas rate equation (equilibrated Kt/V [eKt/V]), and Gotch standardized Kt/V (stdKt/V). RESULTS: Nocturnal HD patients maintained a mean single-session spKt/V of 1.64 throughout the study, similar to that of conventional HD patients (1.73), whereas daily HD patients showed a significant decrease in mean single-session spKt/V (0.93) compared with baseline (t(0)) values. Mean weekly spKt/V values increased from t(0) for both quotidian HD groups (9.08 for nocturnal HD, 5.55 for daily HD) and were higher in both quotidian HD groups compared with conventional HD patients. Weekly eKt/V, stdKt/V, and normalized protein equivalent of nitrogen appearance values showed similar trends. Comparison of the 3 different adequacy models showed an increase in weekly HD doses for both quotidian HD regimens compared with conventional HD; however, percentages of increases from t(0) to follow-up differed according to the model used. The calculated efficiency of dose delivery at the 10-month follow-up comparing daily HD with conventional HD was 257 +/- 26 minutes versus 306 +/- 17 stdKt/V unit delivered, respectively, amounting to almost 1 dialysis-hour saved per stdKt/V unit delivered for daily HD. CONCLUSION: These results show that both quotidian HD regimens are more effective than conventional HD in improving weekly urea clearance measured by spKt/V, stdKt/V, and eKt/V.

Adult↗
PubMed2003

Anthropometrically estimated total body water volumes are larger than modeled urea volume in chronic hemodialysis patients: effects of age, race, and gender.

BACKGROUND: The modeled volume of urea distribution (Vm) in intermittently hemodialyzed patients is often compared with total body water (TBW) volume predicted from population studies of patient anthropometrics (Vant). METHODS: Using data from the HEMO Study, we compared Vm determined by both blood-side and dialysate-side urea kinetic models with Vant as calculated by the Watson, Hume-Weyers, and Chertow anthropometric equations. RESULTS: Median levels of dialysate-based Vm and blood-based Vm agreed (43% and 44% of body weight, respectively). These volumes were lower than anthropometric estimates of TBW, which had median values of 52% to 55% of body weight for the three formulas evaluated. The difference between the Watson equation for TBW and modeled urea volume was greater in Caucasians (19%) than in African Americans (13%). Correlations between Vm and Vant determined by each of the three anthropometric estimation equations were similar; but Vant derived from the Watson formula had a slightly higher correlation with Vm. The difference between Vm and the anthropometric formulas was greatest with the Chertow equation, less with the Hume-Weyers formula, and least with the Watson estimate. The age term in the Watson equation for men that adjusts Vant downward with increasing age reduced an age effect on the difference between Vant and Vm in men. CONCLUSION: The findings show that kinetically derived values for V from blood-side and dialysate-side modeling are similar, and that these modeled urea volumes are lower by a substantial amount than anthropometric estimates of TBW. The higher values for anthropometry-derived TBW in hemodialyzed patients could be due to measurement errors. However, the possibility exists that TBW space is contracted in patients with end-stage renal disease (ESRD) or that the TBW space and the urea distribution space are not identical.

Black or African American↗
PubMed2003

Prescribing an equilibrated intermittent hemodialysis dose in intensive care unit acute renal failure.

BACKGROUND: Prospective, formal, blood-side, urea kinetic modeling (UKM) has yet to be applied in intermittent hemodialysis for acute renal failure (ARF). Methods for prescribing a target, equilibrated Kt/V (eKt/V) are described for this setting. METHODS: Serial sessions (N= 108) were studied in 28 intensive care unit ARF patients. eKt/V was derived using delayed posthemodialyis urea samples and formal, double-pool UKM (eKt/Vref), and by applying the Daugirdas-Schneditz venous rate equation to pre- and posthemodialysis samples (eKt/Vrate). Individual components of prescribed and delivered dose were compared. Prescribed eKt/V values were determined using in vivo dialyzer clearance estimates and anthropometric (Watson and adjusted Chertow) and modeled urea volumes. RESULTS: eKt/Vref (mean +/- SD = 0.91 +/- 0.26) was well-approximated by eKt/Vrate (0.92 +/- 0.25), R= 0.92. Modeled V exceeded Watson V by 25%+/- 29% (P < 0.001) and Adjusted Chertow V by 18%+/- 28% (P < 0.001), although the degree of overestimation diminished over time. This difference was influenced by access recirculation (AR) and use of saline flushes. The median % difference between Vdprate and Watson V was reduced to 1% after adjusting for AR for the 22 sessions with < or =1 saline flush. The median coefficients of variation for serial determinations of Adjusted Chertow V, modeled V, urea generation rate, and eKt/Vref were 2.7%, 12.2%, 30.1%, and 16.4%, respectively. Because of comparatively higher modeled urea Vs, delivered eKt/Vref was lower than prescribed eKt/V, based on Watson V or Adjusted Chertow V, by 0.13 and 0.08 Kt/V units. The median absolute errors of prescribed eKt/V vs. delivered therapy (eKt/Vref) were not large and were similar in prescriptions based on the Adjusted Chertow V (0.127) vs. those based on various double-pool modeled urea volumes (approximately 0.127). CONCLUSION: Equilibrated Kt/V can be derived using formal, double-pool UKM in intensive care unit ARF patients, with the venous rate equation providing a practical alternative. A target eKt/V can be prescribed to within a median absolute error of less than 0.14 Kt/V units using practical prescription algorithms. The causes of the increased apparent volume of urea distribution appear to be multifactorial and deserve further investigation.

Acute Kidney Injury↗
PubMed2003

Prescribing hemodialysis: the role of gender.

Mortality rates remain high in the United States for people who depend on artificial kidney replacement for their existence, and the mortality rates are similar in men and women. However, women differ from men in many respects; some of these ways may have an impact on the response to dialysis through mechanisms that need to be further explored. Observational studies have shown that women respond more readily to a higher dose of dialysis, and recent data from the HEMO clinical trial suggest that women respond to an increase in clearance of low-molecular-weight uremic toxins, whereas men do not. If the findings of these studies prove to be accurate, then we may conclude not only that women require a higher dose of dialysis as currently measured, but we might also expect women to require dialysis sooner during the course of a progressive decline in renal function. The reason for this gender-dependent difference in susceptibility escapes definition at the present time, but size is an obvious confound that can be explored by using current data and in future studies. More detailed analyses of the HEMO data are forthcoming and may shed further light on this question.

Female↗
PubMed2003

Impact of dialysis dose and membrane on infection-related hospitalization and death: results of the HEMO Study.

Infection is the second most common cause of death among hemodialysis patients. A predefined secondary aim of the HEMO study was to determine if dialysis dose or flux reduced infection-related deaths or hospitalizations. The effects of dialysis dose, dialysis membrane, and other clinical parameters on infection-related deaths and first infection-related hospitalizations were analyzed using Cox regression analysis. Among the 1846 randomized patients (mean age, 58 yr; 56% female; 63% black; 45% with diabetes), there were 871 deaths, of which 201 (23%) were due to infection. There were 1698 infection-related hospitalizations, yielding a 35% annual rate. The likelihood of infection-related death did not differ between patients randomized to a high or standard dose (relative risk [RR], 0.99 [0.75 to 1.31]) or between patients randomized to high-flux or low-flux membranes (RR, 0.85 [0.64 to 1.13]). The relative risk of infection-related death was associated (P < 0.001 for each variable) with age (RR, 1.47 [1.29 to 1.68] per 10 yr); co-morbidity score (RR, 1.46 [1.21 to 1.76]), and serum albumin (RR, 0.19 [0.09 to 0.41] per g/dl). The first infection-related hospitalization was related to the vascular access in 21% of the cases, and non-access-related in 79%. Catheters were present in 32% of all study patients admitted with access-related infection, even though catheters represented only 7.6% of vascular accesses in the study. In conclusion, infection accounted for almost one fourth of deaths. Infection-related deaths were not reduced by higher dose or by high flux dialyzers. In this prospective study, most infection-related hospitalizations were not attributed to vascular access. However, the frequency of access-related, infection-related hospitalizations was disproportionately higher among patients with catheters compared with grafts or fistulas.

Catheterization↗
PubMed2002

Effect of dialysis dose and membrane flux in maintenance hemodialysis.

BACKGROUND: The effects of the dose of dialysis and the level of flux of the dialyzer membrane on mortality and morbidity among patients undergoing maintenance hemodialysis are uncertain. METHODS: We undertook a randomized clinical trial in 1846 patients undergoing thrice-weekly dialysis, using a two-by-two factorial design to assign patients randomly to a standard or high dose of dialysis and to a low-flux or high-flux dialyzer. RESULTS: In the standard-dose group, the mean (+/-SD) urea-reduction ratio was 66.3+/-2.5 percent, the single-pool Kt/V was 1.32+/-0.09, and the equilibrated Kt/V was 1.16+/-0.08; in the high-dose group, the values were 75.2+/-2.5 percent, 1.71+/-0.11, and 1.53+/-0.09, respectively. Flux, estimated on the basis of beta2-microglobulin clearance, was 3+/-7 ml per minute in the low-flux group and 34+/-11 ml per minute in the high-flux group. The primary outcome, death from any cause, was not significantly influenced by the dose or flux assignment: the relative risk of death in the high-dose group as compared with the standard-dose group was 0.96 (95 percent confidence interval, 0.84 to 1.10; P=0.53), and the relative risk of death in the high-flux group as compared with the low-flux group was 0.92 (95 percent confidence interval, 0.81 to 1.05; P=0.23). The main secondary outcomes (first hospitalization for cardiac causes or death from any cause, first hospitalization for infection or death from any cause, first 15 percent decrease in the serum albumin level or death from any cause, and all hospitalizations not related to vascular access) also did not differ significantly between either the dose groups or the flux groups. Possible benefits of the dose or flux interventions were suggested in two of seven prespecified subgroups of patients. CONCLUSIONS: Patients undergoing hemodialysis thrice weekly appear to have no major benefit from a higher dialysis dose than that recommended by current U.S. guidelines or from the use of a high-flux membrane.

Adult↗
PubMedDate not supplied

Dialyzer performance in the HEMO Study: in vivo K0A and true blood flow determined from a model of cross-dialyzer urea extraction.

Inlet and outlet blood urea concentrations (Cin and Cout) can be used to directly measure dialyzer performance if simultaneous blood flow measurements (Qb) are available. Dialyzer clearance, for example, is the product of the urea extraction ratio [ER = (Cin - Cout)/Cin] and Qb. Urea concentrations are measured routinely in all hemodialysis clinics, but Qb is usually reported as the product of the pump rotational speed and pump segment stroke volume, which can be inaccurate at high flow rates. Dialyzer urea extraction is also a function of Qb, dialysate flow (Qd), and the membrane permeability-area coefficient (K0A) for urea. To determine true in vivo values for Qb and K0A in the absence of direct flow measurements, we developed a model based on an existing mathematical equation for hemodialyzer ER under conditions of countercurrent flow. Qb, K0A, and other variables were adjusted to fit the modeled ER to ER measured in 1,285 patients treated with Qb that ranged from 200 to 450 ml/min during the HEMO Study. Fitting was performed by least squares nonlinear regression using parametric and nonparametric methods for estimating true flow. As Qb rose above 250 ml/min, both methods for estimating actual Qb showed increasing deviations from the flow reported by the blood pump meter. Modeled values for K0A differed significantly among dialyzer models, ranging from 71% to 96% of the in vitro values. The previously described 14% increase in K0A, as Qd increased in vitro from 500 to 800 ml/min, was much less in vivo, averaging only 5.5 +/- 1.5% higher. Dialyzer reprocessing was associated with a 6.3 +/- 1.0% reduction in K0A and an approximate 2% fall in urea clearance per 10 reuses (p < 0.001). Multiple regression analysis showed a small but significant dialysis center effect on ER but no independent effects of other variables, including the ultrafiltration rate, diabetic status, race, ethnicity, sex, method of reuse, treatment time, access recirculation, and use of central venous accesses. The new algorithm allowed a more accurate determination of true Qb and in vivo K0A in the absence of direct flow measurements in a large population treated with a wide range of blood flow rates. Application of this technique for more than 1000 patients in the HEMO Study confirmed that in vitro measurements using simple crystalloid solutions cannot readily substitute for in vivo measurements of dialyzer function, and permitted a more accurate calculation of each patient's prescribed dialysis dose and urea volume.

Adult↗
PubMedDate not supplied

Defining ASAIO.

Explore the source record for details and available documents.

Animals↗